Virtual Network Embedding with Coordinated Node and Link Mapping N. M. Mosharaf Kabir Chowdhury Muntasir Raihan Rahman and Raouf Boutaba University of Waterloo

Motivation Network Virtualization – Coexistence of multiple virtual networks (VNs) over a shared substrate – Applications Research experiments Future Internet architecture (e.g., Clean-slate) Major challenge – Efficient assignment of substrate network resources to virtual networks requirements June 4, 20142INFOCOM Rio de Janeiro, Brazil

VN Embedding Problem Given: – Single substrate network: G S = (N S, E S ) – Online VN requests: G V = (N V, E V ) – Requirements and Constraints of virtual nodes and virtual links Task: – Assign virtual nodes and links to substrate nodes and links – Allocate resources CPU, bandwidth June 4, 20143INFOCOM Rio de Janeiro, Brazil

VN Embedding Objectives Maximize – Acceptance ratio Percentage of request accepted – Revenue Based on resources requested for a VN Minimize – Cost Based on substrate network resources allocated for embedding VN requests June 4, 20144INFOCOM Rio de Janeiro, Brazil

Virtual Network Embedding 5 C AB DEF GH a bc 10 e fd 20 a bc d e f June 4, 2014 NP-hard INFOCOM Rio de Janeiro, Brazil

Observations Existing heuristics: 1.Disjoint node and link mapping 2.Ignore (completely) location constraints on virtual nodes Our approach – Node mapping influences link mapping – Location constraints take the front seat Meta-VN request June 4, 20146INFOCOM Rio de Janeiro, Brazil

Substrate Graph Augmentation 7 C AB DEF GH a bc 10 a b c 12 June 4, 2014INFOCOM Rio de Janeiro, Brazil

Objective Flow variables: – Multi-commodity flow constraints Binary variables: – Exactly one substrate node is selected for each meta-node – At most one meta-node is mapped onto a substrate node Mixed Integer Program June 4, 20148INFOCOM Rio de Janeiro, Brazil α, β: Tuning parameters R: Remaining capacity

Mixed Integer Program Solution 9 C AB DEF GH a bc 10 a b c 12 June 4, 2014 NP-hard INFOCOM Rio de Janeiro, Brazil

LP Relaxation Relax the binary constraints on the x variable Problem 1: x values do not select single substrate nodes for every meta-node – Use rounding techniques (e.g., deterministic, randomized) Problem 2: x values are inconsistent – Use the product of x and f while rounding June 4, INFOCOM Rio de Janeiro, Brazil

FINALIZATION LINK MAPPING NODE MAPPING INITIALIZATION ViNEYard (D-ViNE & R-ViNE) 11 For each VN request: – Augment the substrate graph – Solve the resulting LP – For each virtual node: Calculate the probability for each meta-node to be selected for the corresponding virtual node Selection: – D-ViNE: Select the meta-link with the highest probability – R-ViNE: Select a meta-link randomly with the calculated probability – Use MCF to map virtual edges – If the VN request is accepted Update residual capacities of the substrate resources June 4, 2014INFOCOM Rio de Janeiro, Brazil

Performance Evaluation Compared Algorithms Description D-ViNEDeterministic Node Mapping with Splittable Link Mapping using MCF R-ViNERandomized Node Mapping with Splittable Link Mapping using MCF G-SPGreedy Node Mapping with Shortest Path Based Link Mapping G-MCFGreedy Node Mapping with Splittable Link Mapping using MCF D-ViNE-SPDeterministic Node Mapping with Shortest Path Based Link Mapping D-ViNE-LBDeterministic Node Mapping with Splittable Link Mapping using MCF, where α uv = β w = 1, for all u, v, w Є N S June 4, INFOCOM Rio de Janeiro, Brazil

Simulation Setup Substrate network – 50 nodes in a 25x25 grid with 0.5 link probability – CPU/BW uniformly distributed in the range: units VN requests – Poisson arrival rates from 4 VN requests 100 time units – Exponentially distributed lifetime of 1000 time units – 2-10 nodes with 0.5 link probability Tools: GT-ITM (Georgia Tech Internet Topology Models), GLPK (GNU Linear Programming Toolkit) June 4, 2014INFOCOM Rio de Janeiro, Brazil13

Acceptance Ratio June 4, INFOCOM Rio de Janeiro, Brazil

Revenue Vs Cost RevenueCost June 4, INFOCOM Rio de Janeiro, Brazil

Link Utilization June 4, INFOCOM Rio de Janeiro, Brazil

Conclusions ViNEYard Algorithms – Improved correlation between the node mapping and the link mapping phases – Increased acceptance ratio and revenue with decreased cost Ongoing and Future Work – Window-based extension to D-ViNE and R-ViNE a.k.a. WiNE – Extension to inter-domain scenario a.k.a. PolyViNE – Approximation factors for D-ViNE and R-ViNE June 4, INFOCOM Rio de Janeiro, Brazil

June 4, Thank You! Questions? INFOCOM Rio de Janeiro, Brazil

BACKUP SLIDES June 4, INFOCOM Rio de Janeiro, Brazil

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D-ViNE June 4, INFOCOM Rio de Janeiro, Brazil

R-ViNE June 4, INFOCOM Rio de Janeiro, Brazil

Resource Utilization Node UtilizationLink Utilization June 4, INFOCOM Rio de Janeiro, Brazil

Effect of Increasing Load 25June 4, 2014INFOCOM Rio de Janeiro, Brazil